[Storm SQL] Add built-in socket datasource to runtime

Details

Description

Currently Storm SQL requires Kafka to input source, and also require Kafka or Redis to output source. This is OK for production, but users might want to test their SQL statements before associating their table to actual data sources in development phase, even we support 'explain'.

Supporting socket as data source will greatly help users to test, especially with 'netcat' available on OSX, and also expected to be available from Linux distros.